Enhanced pulmonary absorption following aerosol administration of mucoadhesive powder microspheres

Mucoadhesive, hydroxypropylcellulose (HPC) microspheres were prepared for powder inhalation and their feasibility for enhancing pulmonary drug absorption was investigated. Respirable-sized microspheres, incorporating crystalline or amorphous fluorescein (used as a model drug), were prepared by spray-drying aqueous or ethanol HPC systems, respectively. These were prepared from a variety of HPC grades (SL, L, M and H types) in different fluorescein-HPC ratios (1:1-1:10). The microspheres were administered to tracheally-intubated guinea pigs as powder aerosols and their fluorescein pharmacokinetics studied, and compared to those for pure crystalline fluorescein ('control'). All microspheres were prepared and aerosolized within a MMAD range of 1.3-2.6 microm (GSD< or =2.1). Fluorescein's dissolution was increased in the amorphous form by 6.5-fold when compared to the crystalline material (83.9-87.2 vs. 13.5 microg/ml, respectively). Poor dissolution for the 'control' crystalline fluorescein appeared to be rate-determined, which showed bi-phasic absorption profiles (T(max)=60 min), simultaneously competing with mucociliary clearance out of the lower airways. While the crystalline/HPC microspheres prolonged absorption, the amorphous fluorescein/HPC microspheres showed rapid absorption with T(max)=0 min (immediately after the administration had terminated). This was explained by enhanced fluorescein dissolution and was consistently observed irrespective of the fluorescein-HPC ratio or HPC grade. However, the microspheres with the least viscous HPC-SL and the lowest fluorescein-HPC ratio (1:1) failed to enhance bioavailability, presumably because the mucociliary clearance was undisturbed. In contrast, the microspheres with the highly viscous HPC-H with ratios > or = 1:4 successfully enhanced absorption, achieving 88.0% bioavailability by virtue of HPC increasing the dissolution and retarding the mucociliary clearance.

Phenotypic changes of adrenomedullin receptor components, RAMP2, and CRLR mRNA expression in cultured rat vascular smooth muscle cells

Adrenomedullin is known to inhibit cell proliferation in cultured rat vascular smooth muscle cells, through a cAMP-dependent process. The calcitonin receptor-like receptor could function as an adrenomedullin receptor when co-expressed with receptor activity-modifying protein 2. To determine whether vascular adrenomedullin receptor components, the calcitonin receptor-like receptor and the receptor activity-modifying protein 2, phenotypically change during in vitro culture conditions, we examined the expression of adrenomedullin receptor components, adrenomedullin-induced cAMP production, and the inhibition of cell proliferation in culture rat vascular smooth muscle cells during serial passages. The results demonstrated that the receptor activity-modifying protein 2 and calcitonin receptor-like receptor mRNAs increased in a passage-dependent manner in rat vascular smooth muscle cells. Furthermore, the responses of both the elevation of cAMP and the inhibition of cell proliferation became larger in vascular smooth muscle cells with an increasing number of passages. The results suggest that the increase in functional AM receptor during phenotypic change may in part contribute to the development of vascular lesions, such as in atherosclerosis.

Alteration of the adrenomedullin receptor components gene expression associated with the blood pressure in pregnancy-induced hypertension

Adrenomedullin (AM) is a potent vasodilator. Pregnancy-induced hypertension (PIH) is a common cause of maternal or fetal mortality. We measured the changes of adrenomedullin receptor components gene expression, receptor activity-modifying protein 2 (RAMP2) and calcitonin receptor-like receptor (CRLR), at feto-maternal tissues in human normotensive pregnant women and pregnancy-induced hypertensive women by Northern blot analysis. Samples of the placenta, uterine muscle, umbilical artery, and fetal membranes were obtained from each patient under informed consent. RAMP2 mRNA significantly decreased in the umbilical artery (54%, P < 0.01) and uterus (53%, P < 0.01) of the patients with PIH. CRLR mRNA also significantly decreased in both tissues of the patients with PIH. On the other hand, the RAMP2 mRNA was significantly increased in the fetal membrane of the patients with PIH. In addition, there was a significant negative correlation between the RAMP2 mRNA levels in the umbilical artery (systolic; r = -0.623, P < 0.01, diastolic; r = -0.552, P < 0.01) and uterine muscle (systolic; r = -0.563, P < 0.01, diastolic; r = -0.553, P< 0.01) and blood pressure. However, there was no correlation between the mRNA level and blood pressure in fetal membrane and placenta, suggesting that there is no close relationship to the pathogenesis in PIH. These findings suggested that the reduced expression of adrenomedullin receptor component in umbilical artery and uterus may have some role in PIH.

Genomic structure and insulin-mediated repression of the aquaporin adipose (AQPap), adipose-specific glycerol channel

Aquaporin adipose (AQPap) is a putative glycerol channel in adipocytes (Kishida, K., Kuriyama, H., Funahashi, T., Shimomura, I., Kihara, S., Ouchi, N., Nishida, M., Nishizawa, H., Matsuda, M., Takahashi, M., Hotta, K., Nakamura, T., Yamashita, S., Tochino, Y., and Matsuzawa, Y. (2000) J. Biol. Chem. 275, 20896-20902). In the current study, we examined the genomic structure of the mouse AQPap gene and its regulation by insulin. The mouse AQPap gene spanned 12 kilobase pairs in chromosome 4 and consisted of 8 exons and 7 introns. The first two exons, designated exon 1 and exon 1', are alternatively spliced to common exon 2, and thus the AQPap gene possessed two potential promoters. The exon 1-derived transcript is dominant in both adipose tissues and adipocytes on the basis of RNase protection assay and promoter analysis. The mRNA increased after fasting and decreased with refeeding. Insulin deficiency generated by streptozotocin enhanced the mRNA in adipose tissue. Insulin down-regulated AQPap mRNA in 3T3-L1 adipocytes. The AQPap promoter contained heptanucleotide sequences, TGTTTTT at -443/-437, similar to the insulin-response element identified previously in the promoters of insulin-repressed genes. Deletion and single base pair substitution analysis of the promoter revealed that these sequences were required for insulin-mediated repression of AQPap gene transcription. The phosphatidylinositol 3-kinase pathway was involved in this inhibition. We conclude that insulin represses the transcription of AQPap gene via insulin response element in its promoter. Sustained up-regulation of AQPap mRNA in adipose tissue in the insulin-resistant condition may disturb glucose homeostasis by increasing plasma glycerol.

Glycogen debranching enzyme in bovine brain

Glycogen debranching enzyme was partially purified from bovine brain using a substrate for measuring the amylo-1,6-glucosidase activity. Bovine cerebrum was homogenized, followed by cell-fractionation of the resulting homogenate. The enzyme activity was found mainly in the cytosolic fraction. The enzyme was purified 5,000-fold by ammonium sulfate precipitation, anion-exchange chromatography, gel-filtration, anion-exchange HPLC, and gel-permeation HPLC. The enzyme preparation had no alpha-glucosidase or alpha-amylase activities and degraded phosphorylase limit dextrin of glycogen with phosphorylase. The molecular weight of the enzyme was 190,000 and the optimal pH was 6.0. The brain enzyme differed from glycogen debranching enzyme of liver or muscle in its mode of action on dextrins with an alpha-1,6-glucosyl branch, indicating an amino acid sequence different from those of the latter two enzymes. It is likely that the enzyme is involved in the breakdown of brain glycogen in concert with phosphorylase as in the cases of liver and muscle, but that this proceeds in a somewhat different manner. The enzyme activity decreased in the presence of ATP, suggesting that the degradation of brain glycogen is controlled by the modification of the debranching enzyme activity as well as the phosphorylase.

Interaction between the RGS domain of RGS4 with G protein alpha subunits mediates the voltage-dependent relaxation of the G protein-gated potassium channel

1. In native cardiac myocytes, there is a time dependence to the G protein-gated inwardly rectifying K(+) (K(G)) channel current during voltage steps that accelerates as the concentration of acetylcholine is increased. This phenomenon has been called 'relaxation' and is not reproduced in the reconstituted Kir3.1/Kir3.4 channel in Xenopus oocytes. We have shown that RGS4, a regulator of G protein signalling, restores relaxation to the reconstituted Kir3.1/Kir3.4 channel. In this study, we examined the mechanism of this phenomenon by expressing various combinations of membrane receptors, G proteins, Kir3.0 subunits and mutants of RGS4 in Xenopus oocytes. 2. RGS4 restored relaxation to K(G) channels activated by the pertussis toxin (PTX)-sensitive G protein-coupled m(2)-muscarinic receptor but not to those activated by the G(s) protein-coupled beta(2)-adrenergic receptor. 3. RGS4 induced relaxation not only in heteromeric K(G) channels composed of Kir3.1 and Kir3.4 but also in homomeric assemblies of either an active mutant of Kir3.1 (Kir3.1/F137S) or an isoform of Kir3.2 (Kir3.2d). 4. Truncation mutants of RGS4 showed that the RGS domain itself was essential to reproduce the effect of wild-type RGS4 on the K(G) channel. 5. The mutation of residues in the RGS domain which interact with the alpha subunit of the G protein (G(alpha)) impaired the effect of RGS4. 6. This study therefore shows that interaction between the RGS domain and PTX-sensitive G(alpha) subunits mediates the effect of RGS4 on the agonist concentration-dependent relaxation of K(G) channels.

[The validity of revised death certificates (ICD-10) for ischemic heart disease in Oita City, Japan]

PURPOSE

Mortality statistics have recorded an increased number of deaths from ischemic heart disease (IHD) since death certificates were revised to reflect the International Classification of Diseases, tenth revision (ICD-10) in Japan, in 1995. However, it remains unclear whether the validity of IHD diagnosis improved after this revision.

METHODS

We conducted the Oita Cardiac Death Survey to validate IHD certified deaths that occurred among residents aged 25-74 in Oita City, Japan (mean population = 273,000). Of the eligible 342 fatalities, 328 cases (95.0%) were examined by a review of the medical records and/or interviews with physicians. The MONICA criteria were applied and provided a reference standard against which to assess the validity of certified fatal IHD. Sensitivity (Se), positive predictive value (PPV), specificity (Sp) and negative predictive value (NPV) for IHD as the cause of death were analyzed, assuming that all validated IHD deaths were true. Multivariate logistic models were used to determine associations of false positive and false negative cases with sex, age at time of death and place of death.

RESULTS

Vital statistics revealed 273 fatalities to be due to cardiac disease, including 143 from acute myocardial infarctions (AMI), 27 from other IHD, 52 from heart failure and 51 from other heart diseases. After validation, 25 'definite fatal AMI' and 71 'possible fatal AMI or IHD death' were identified among all subjects according to the MONICA criteria. In all, Se, PPV, Sp and NPV for IHD certified as the cause of death were 86.5% (95% Cl: 77.6-92.3), 50.3% (42.5-58.1), 64.7% (58.1-70.7), and 92.0% (86.5-95.5), respectively. PPV among persons aged 25-54 years was remarkably decreased. PPV and Sp among out-of-hospital deaths were significantly lower than for in-hospital deaths. Multivariate logistic models revealed out-of-hospital deaths and being aged 25-54 years to be significant predictors of false positive cases (odds ratio (OR) = 2.03, P < 0.001 versus in-hospital deaths and OR = 2.79, P < 0.05 versus ages of 65-74 years, respectively).

CONCLUSIONS

Because false positive cases increased among certified IHD deaths after the revision, PPV and Sp percentages decreased. Out-of-hospital deaths and being aged 25-54 years were associated with increased possibility of false positive. Given our findings, IHD deaths in vital statistics may increase due to the tendency of physicians to certify IHD as the cause of death in cases without clear sign suggestive of other causes.

Effect of a hypocaloric diet on adrenomedullin and natriuretic peptides in obese patients with essential hypertension

We examined the effect of a hypocaloric diet on adrenomedullin (AM), atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) in 12 obese patients with essential hypertension (age, 48-81 years; body mass index, 26-34 kg/m2). For the initial week, a standard diet of 2000 kcal/day was given, followed by 3 weeks of a hypocaloric diet of 850 kcal/day, with a constant intake of sodium. The patients lost 3.7 +/- 0.2 kg body weight during the hypocaloric diet period (p < 0.0001). The decrease in blood pressure during the study period was 10.3 +/- 3.6 mmHg systole (p = 0.017) and 4.2 +/- 3.2 mmHg diastole (NS). Plasma AM concentration was decreased significantly from 4.88 +/- 0.46 to 3.97 +/- 0.38 pmol/l by the hypocaloric diet (p = 0.004). Plasma ANP and BNP concentrations were also decreased significantly by the hypocaloric diet (p = 0.042 for each). These results demonstrate, for the first time, that plasma AM concentration as well as plasma ANP and BNP concentrations are decreased by a hypocaloric diet in obese patients with essential hypertension. These vasodilator peptides may act against further elevation in blood pressure in obese patients with essential hypertension.

Sacrococcygeal teratoma with hydrops fetalis and bilateral hydronephrosis

A 29-year-old Japanese primipara with fetal sacrococcygeal teratoma and hydronephrosis was referred to our department at 22 weeks of gestation. The preload index of the inferior vena cava (PLI) was 0.75 and fetal cardiac failure was suspected at 28 weeks of gestation. The sodium and chloride concentrations and osmolarity of the fetal urine were 96 mEq/L, 81 mEq/L and 204 mOsm/L, respectively, and we predicted a good renal function. Then, a vesico-amniotic shunting operation was performed at 28 weeks of gestation to keep the renal function and PLI decreased 0.41 after this operation. At 30 weeks of gestation, the fetus was delivered by a cesarean section owing to preterm PROM and a huge growing sacrococcygeal teratoma. The baby was female, weighing 2,020 g, and the 1 minute Apgar score was 1. She died almost 7 hours after birth due to respiratory insufficiency. An autopsy confirmed bilateral hydronephrosis, urethral stenosis, sacrococcygeal immature teratoma, and pulmonary hypoplasia. The size of this tumor revealed 80 x 70 x 45 mm in intrapelvic cavity and 130 x 90 x 50 mm out of body, and this tumor was classified as Type II according to the American Academy of Pediatrics Surgery Section classification.

[Learning from fungus allergy in atopic dermatitis patients]

It has been recognized that there are considerable variations in their skin reactivity to environmental allergens as well as in immunoreactivities, even in AD patients with similar signs and symptoms. Some AD patients have high serum IgE antibody levels, while others show low levels. There are also differences in the kinds of triggering factors that are related to the development and maintenance of AD, e.g., allergic or non-allergic. Even among AD patients with high titers of serum IgE antibodies, the kinds and number of allergens involved in the exacerbation of AD are different and can change with time. The types of the underlying allergic reactions vary as well, i.e., some show immediate reactions, while others show delayed type hypersensitivity responses to environmental allergens. Thus, even AD patients diagnosed by the established criteria may have remarkably different backgrounds. When we looked over our published data, we noticed that there were differences in levels of IgE RAST and skin reactions between AD with atopic respiratory diseases (ARD) and pure AD without ARD. Levels of IgE RAST against airborne allergens, which come into the body mainly through the respiratory tract, were higher in AD with ARD, while those against allergens such as Candida albicans and Malassezia furfur, which can colonize on the skin, were higher in pure AD. In addition to these Th2-mediated immunological abnormalities, Th1-mediated DTH reaction and lymphocyte proliferation indices against airborne allergens were remarkably low in AD with ARD, whereas those against Candida albicans and Malassezia furfur were relatively preserved, although they were lower than those found in normal subjects. We understand from these findings that routes of allergen entry are important for the outcome of the resultant allergic reactions. This point of view is important answering questions such as how AD develops and how it can be prevented from the insults of each allergen.

Redox regulation of the nuclear receptor

Redox regulation is currently considered a mode of signal transduction for coordinated regulation of a variety of cellular processes. Transcriptional regulation of gene expression is also influenced by the cellular redox state, for example, through the oxidoreductive modification of transcription factors. The nuclear receptors act as ligand-dependent transcription factors and are considered to be one of the key regulators of essential biological processes. Using a glucocorticoid receptor as a model, we show that redox regulation of receptor function is one of the dynamic cellular responses to environmental stimuli.

Chromosome mapping and expression of human tip49 family genes

TBP-interacting protein 49 (TIP49) was originally identified as a TBP-binding protein, and two related proteins are encoded by individual genes, tip49a and b. Although the function of this gene family has not been elucidated, they are supposed to play a critical role in nuclear events because they interact with various kinds of nuclear factors and have DNA helicase activities. At least, TIP49a has been suggested to act as an autoantigen in some patients with autoimmune diseases. In this study, we investigated the chromosome positions of this family of genes. Human tip49a and tip49b genes were mapped on 3q21 and 19q13.2, respectively. Consistent with the notion that tip49 family genes are essential for cell growth, Northern blot analysis demonstrated that both genes are expressed ubiquitously in human tissues. It is worthy of notice that the testes contained large amounts of the both transcripts. These results are consistent with our previous results from tissue distribution analysis for of TIP49 proteins.

Functional Kir7.1 channels localized at the root of apical processes in rat retinal pigment epithelium

1. The inwardly rectifying K+ channel current (IK(IR)) recorded from isolated retinal pigmented epithelial (RPE) cells showed poor dependence on external K+ ([K+]o) and low sensitivity to block by Ba2+. We examined the molecular identity and specific subcellular localization of the KIR channel in RPE cells. 2. The Kir7.1 channel current heterologously expressed in HEK293T cells (human embryonic kidney cell line) showed identical properties to those of the RPE IK(IR), i.e. poor dependence on [K+]o and low sensitivity to Ba2+ block. 3. Expression of Kir7.1 mRNA and protein was detected in RPE cells by RT-PCR and immunoblot techniques, respectively. 4. Immunohistochemical studies including electron microscopy revealed that the Kir7.1 channel was localized specifically at the proximal roots of the apical processes of RPE cells, where Na+,K+-ATPase immunoreactivity was also detected. 5. The middle-distal portions of apical processes of RPE cells in the intact tissue exhibited immunoreactivity of Kir4.1, a common KIR channel. In the isolated RPE cells, however, Kir4.1 immunoreactivity was largely lost, while Kir7.1 immunoreactivity remained. 6. These data indicate that the only IK(IR) recorded in isolated RPE cells is derived from the functional Kir7.1 channel localized at the root of apical processes. Co-localization with Na+,K+-ATPase suggests that the Kir7.1 channel may provide the pathway for recycling of K+ to maintain pump activity and thus is essential for K+ handling in RPE cells.

Rapid detection of chromosome aneuploidies by prenatal interphase FISH (fluorescence in situ hybridization) and its clinical utility in Japan

OBJECTIVE

The purpose of this study was to assess the accuracy, informative rate, detection rate, and clinical utility of prenatal interphase fluorescence in situ hybridization (FISH) analysis of amniotic fluid samples from Japanese women.

METHODS

Amniotic fluid specimens from 2,639 Japanese women were received for prenatal interphase FISH and chromosome analysis. A questionnaire was designed to evaluate FISH clinical utility by collaboration sites.

RESULTS

Based on 2,319 tested samples, the accuracy (100%), informative (94%), and detection (87.6%) rates were all high. The accuracy (100%), informative (90.2%), and detection (90.0%) rates were also remarkable in third-trimester pregnancies. We perceive significant advantages from this test regarding medical management and patient satisfaction.

CONCLUSIONS

This novel report shows that in Japan prenatal interphase FISH testing is highly informative and accurate, not only in second-trimester pregnancies but also in third-trimester pregnancies. This test provides advantages to both physicians and patients, provided that its capabilities and limitations are understood.

Effects of cilnidipine, a novel dihydropyridine calcium antagonist, on autonomic function, ambulatory blood pressure and heart rate in patients with essential hypertension

AIMS

The aim of the present study was to evaluate the effects of cilnidipine, a novel dihydropyridine calcium antagonist, on autonomic function, ambulatory blood pressure and heart rate in patients with essential hypertension.

METHODS

Ten inpatients with mild to moderate essential hypertension (four men and six women; age: 44-64 years) underwent a drug-free period for 7 days and a treatment period with cilnidipine 10 mg orally for another 7 days, in a randomized crossover study. On the sixth day of each period, they underwent autonomic function tests including a mental arithmetic test, a cold pressor test and a Valsalva manoeuvre. After these tests, 24 h ambulatory blood pressure, heart rate, and the electrocardiogram R-R intervals were monitored every 30 min. A power spectral analysis of R-R intervals was performed to obtain the low-and high-frequency components.

RESULTS

Cilnidipine significantly decreased the 24 h blood pressure by 6.5 +/- 1.7 mm Hg systolic (mean +/- s.e.mean; P < 0.01) and 5.0 +/- 1.1 mmHg diastolic (P < 0.01), whereas cilnidipine did not change heart rate or any indices of power spectral components. During the cold pressor test, the maximum change in systolic blood pressure and percentage changes in both systolic and diastolic blood pressures were significantly lower during the treatment period with cilnidipine than during the drug-free period. The baroreflex sensitivity measured from the overshoot phase of the Valsalva manoeuvre did not differ significantly between the two periods.

CONCLUSIONS

Cilnidipine is effective as a once-daily antihypertensive agent and causes little influence on heart rate and the autonomic nervous system in patients with mild to moderate essential hypertension. Moreover, it is suggested that cilnidipine has an additional clinical benefit in the inhibition of the pressor response induced by acute cold stress.

Triple marker screening for trisomy 21, trisomy 18 and open neural tube defects in singleton pregnancies of native Japanese pregnant women

OBJECTIVE

To report the results of prenatal triple marker screening on a population of Japanese pregnant women.

METHODS

From April 1994 through March 1999, a total of 32,925 native Japanese women with singleton pregnancies requested a triple marker-screening test. Multiples of the median values for 3 markers and individual risks for each patient were calculated following adjustment for the Japanese weight correction factor. The risk cut-off values used for Down syndrome (T21), open spina bifida (OSB) and trisomy 18 (T18) were 1: 295, 1: 290, and 1: 100, respectively. Follow-up information was collected postpartum and statistically analyzed.

RESULTS

Detection rates (DR) of T21 for women less than 35 years, over 35 years and overall were 58, 94, and 83%, respectively. DR of T18 for women less than 35 years, over 35 years and overall were 75, 79, and 79%, respectively. DR of open neural tube defects (ONTD) was 100%.

CONCLUSIONS

The first cumulative data of an intervention program and prospective follow-up studies in Japan have proven to be similar to other published reports. Individual risk values were calculated for each pregnancy for T21, T18 and ONTD. This screening program is more effective than age-dependent screening for detecting T21, T18 and ONTD pregnancies.

Functional modulation of the mineralocorticoid receptor by cis-diamminedichloroplatinum (II)

BACKGROUND

Renal salt wasting and hypotension are some of the frequent complications in patients treated with cis-diamminedichloroplatinum (II) (cDDP), and it is suggested that cDDP produces an abnormality in the renin-angiotensin system. However, not only the underlying mechanism but also prophylactic treatment of this cDDP toxicity remains unknown. In the present study, we investigated the molecular mechanism of this cDDP-induced disturbance of renal sodium handling with focusing on the effect of cDDP on mineralocorticoid receptor (MR) function.

METHODS

The effect of cDDP was studied on nuclear translocation, DNA binding activity, and transactivation function of the MR.

RESULTS

In a transient transfection assay, cDDP suppressed MR-dependent reporter gene expression. This cDDP-mediated repression of MR function, at least in part, is suggested to be due to the generation of reactive oxygen species and a subsequent decrease in ligand-dependent nuclear translocation and suppression of the interaction with DNA of the MR. This redox-dependent repression of MR function both in vitro and in vivo was reversed by treatment with reducing reagents. Moreover, cDDP, most possibly via formation of DNA adducts, inhibited MR-DNA interaction in a redox-independent fashion.

CONCLUSIONS

MR function is impaired by cDDP at multiple levels, via redox-dependent and -independent mechanisms.

Histological features of cirrhosis with hepatitis C virus for prediction of hepatocellular carcinoma development; a prospective study

The histological features of pre-neoplastic lesions in HCV-associated cirrhosis remain uncertain. The aim of this prospective study was to elucidate histological features for predicting the development of hepatocellular carcinoma (HCC). A cohort of 72 consecutive patients with hepatitis C-associated cirrhosis, which was diagnosed by histology investigated for development of HCC. Seven histological features including small cell dysplasia (SCD) and large cell dysplasia (LCD) of liver cirrhosis were evaluated with regard to the development of HCC. In addition, proliferation and apoptosis were investigated using immunohistochemistry by proliferating cell nuclear antigen and TUNEL method, respectively. At enrollment, SCD was observed in the biopsy specimens of 18 out of 72 (25.0%) patients and LCD was observed in 20 out of 72 (27.8%). Twenty eight out of 72 patients (38.9%) developed HCC during a mean follow-up period of 72.4 months. Among the histological parameters, SCD, active inflammation and complete nodule were statistically significant factors for the cumulative probability of developing HCC. However, LCD did not appear to be important for HCC development. In multivariate analysis, SCD was the highest independent risk factor for HCC. Samples with SCD demonstrated a higher proliferative rate and a lower apoptotic rate than normal hepatocytes or samples with LCD. These results indicate that SCD is a major risk factor for HCC. Careful assessment of liver histology may be important in order to predict HCC development in patients with HCV-related cirrhosis.

Mechanism of regulation of the hypoxia-inducible factor-1 alpha by the von Hippel-Lindau tumor suppressor protein

In normoxic cells the hypoxia-inducible factor-1 alpha (HIF-1 alpha) is rapidly degraded by the ubiquitin-proteasome pathway, and activation of HIF-1 alpha to a functional form requires protein stabilization. Here we show that the product of the von Hippel-Lindau (VHL) tumor suppressor gene mediated ubiquitylation and proteasomal degradation of HIF-1 alpha under normoxic conditions via interaction with the core of the oxygen-dependent degradation domain of HIF-1 alpha. The region of VHL mediating interaction with HIF-1 alpha overlapped with a putative macromolecular binding site observed within the crystal structure of VHL. This motif of VHL also represents a mutational hotspot in tumors, and one of these mutations impaired interaction with HIF-1 alpha and subsequent degradation. Interestingly, the VHL binding site within HIF-1 alpha overlapped with one of the minimal transactivation domains. Protection of HIF-1 alpha against degradation by VHL was a multistep mechanism, including hypoxia-induced nuclear translocation of HIF-1 alpha and an intranuclear hypoxia-dependent signal. VHL was not released from HIF-1 alpha during this process. Finally, stabilization of HIF-1 alpha protein levels per se did not totally bypass the need of the hypoxic signal for generating the transactivation response.

A notable example of an evolutionary conserved gene: studies on a putative DNA helicase TIP49

TIP49a (just called as simply TIP49 in previous reports [Kanemaki et al., 1997; Makino et al., 1998]) was found in a rat nuclear protein complex that included the TATA-binding protein. TIP49a possesses multiple sequence motifs for ATPase and DNA helicase. Since TIP49a structurally resembles prokaryotic DNA helicase RuvB, TIP49a is resumed to be a putative DNA helicase. We demonstrated TIP49a-related gene(s) in variety organisms from human to archaea. Amino acid identities expressed as aligned scores of human, yeast, and A. fulgidus TIP49a gene counterparts to the rat sequence were 99, 67, and 46, respectively. Strikingly, two homologous regions of mammalian TIP49a and bacterial RuvB exhibited an aligned score of 17-38. We demonstrated that the eukaryotic TIP49a counterparts were immunologically conserved. These lines of evidence show that the TIP49a gene is a notable example of a highly conserved gene among organisms. An extensive homology search revealed another class of TIP49-related gene in the eukaryotes, designated as TIP49b. Moreover, a phylogenetical study suggested that archaeal TIP49 genes belong to the TIP49b ancestor but not to the TIP49a one and that TIP49a evolved from TIP49b in accordance with divergence of archaea and eukarya. The TIP49 gene family is thought to play a fundamental role in a biological activity.

Structural analysis of N-linked sugar chains of human blood clotting factor IX

The structures of N-glycans of human blood clotting factor IX were studied. N-Glycans liberated by hydrazinolysis were N-acetylated and the reducing-end sugar residues were tagged with 2-aminopyridine. The pyridylamino (PA-) sugar chains thus obtained were purified by HPLC. Each PA-sugar chain was analyzed by two-dimensional sugar mapping combined with glycosidase digestion. The major structures of the N-linked sugar chains of human factor IX were found to be sialotetraantennary and sialotriantennary chains with or without fucose residues. These highly sialylated sugar chains are located on the activation peptide of the protein.

Emergent mechanisms in multiple pattern generation of the lobster pyloric network

By using a hard-wired oscillator network, multiple pattern generation of the lobster pyloric network is simulated. The network model is constructed using a relaxation oscillator representing an oscillatory or quiescent (i.e. steady-state) neuron. Modulatory inputs to the network are hypothesized to cause changes in the dynamical properties of each pyloric neuron: the oscillatory frequency, the postinhibitory rebound property, and the resting membrane potential. Changes in each of these properties are induced by changing appropriate parameters of the oscillator. By changing seven parameters of the network as a whole, modulatory input-dependent patterns are successfully simulated.

Intraspecific variation in Cannabis sativa L. based on intergenic spacer region of chloroplast DNA

We analyzed the nucleotide sequences of the non-coding region of chloroplast DNA: the intergenic spacer between trnL (UAA) 3'exon and trnF (GAA). Two kinds of sequence, "type-1" and "type-2," were detected in 33 populations of Cannabis sativa. The length of the "type-1" fragment was 354 bp. In contrast, the "type-2" fragment from 3 populations was 353 bp long, with only one base deletion compared to "type-1." The fragment length from Humulus lupulus was 353 bp with a 1-bp deletion, and ten 1-bp substitutions compared to the sequences from C. sativa "type-1." Furthermore, we could clearly identify differences between C. sativa and H. lupulus using single-strand conformation polymorphism of PCR products (PCR-SSCP) analysis.

Effects of diltiazem retard on ambulatory blood pressure and heart rate variability in patients with essential hypertension

BACKGROUND

Dihydropyridine calcium antagonists increase heart rate due to reflex activation of the sympathetic nervous system, although these effects are less obvious for long-acting agents.

OBJECTIVE

To study the effects of diltiazem retard, a long-acting nondihydropyridine calcium antagonist, on 24h blood pressure, heart rate and autonomic nerve activity in patients with essential hypertension.

DESIGN

Randomized crossover design.

METHODS

Thirteen patients [five men and eight women, aged 64+/-2 years (mean+/-SEM)] were administered placebo or diltiazem retard (100-200mg once daily) for 4 weeks each. Ambulatory monitoring of blood pressure and heart rate, and electrocardiography were carried out at the end of each period using a multibiomedical recorder (TM-2425). Autonomic nerve activity was evaluated by power spectral analysis of variability of heart rate using the high-frequency component as an index of parasympathetic nerve activity and the ratio of the low-frequency component and the high-frequency component as an index of sympathovagal balance.

RESULTS

Treatment with diltiazem retard significantly decreased 24h average blood pressure and heart rate by 11.6+/-3.6/5.7+/-1.8mmHg and 5.0+/-1.1 beats/min, respectively. The changes in daytime and night-time values were comparable. Diltiazem retard also significantly decreased daytime and 24h low:high-frequency-component ratio (2.0+/-0.2 versus 1.7+/-0.2 and 1. 8+/-0.2 versus 1.6+/-0.2, respectively).

CONCLUSIONS

These results indicate that diltiazem retard is effective as a once-daily antihypertensive agent and has favorable effects on heart rate and the autonomic nervous system.

Processing pathway deduced from the structures of N-glycans in Carica papaya

A processing The processing pathway of N-glycans in Carica papaya was deduced from the structures of N-glycans. The N-glycans were liberated by hydrazinolysis followed by N-acetylation. Their reducing-end sugar residues were tagged with 2-aminopyridine and the pyridylamino (PA-) sugar chains thus obtained were purified by HPLC. Eleven PA-sugar chains were found, and their structures were analyzed by two-dimensional sugar mapping combined with partial acid hydrolysis and exoglycosidase digestion. The structures of the N-glycans were of the highmannose types with xylose and fucose; however, among them two new N-glycans, Manalpha1-6(Manalpha1-3)Manalpha1-6(Xylbeta1-2)+ ++Manbeta1-4GlcNAcbeta1- 4(Fucalpha1-3)GlcNAc and Manalpha1-3Manalpha1-6(Xylbeta1-2)Manbeta1-4G lcNAcbeta1-4(Fucalpha1-3 )GlcNAc, were found. Judging from these structures together with Manalpha1-6(Manalpha1-3)Manalpha1-6(Manalpha1-3) (Xylbeta1-2)Manbeta1- 4GlcNAcbeta1-4(Fucalpha1-3)GlcNAc reported previously [Shimazaki, A., Makino, Y., Omichi, K., Odani, S., and Hase, S. (1999) J. Biochem. 125, 560- 565], a processing pathway for N-glycans in C. papaya is inferred in which the activity of Golgi alpha-mannosidase II is incomplete.